1. Field of the Invention
The invention relates generally to keepers for idler rolls which lock the ends of a pair of adjacent rolls in fixed position within a bracket.
2. Description of the Prior Art
The desirability of providing a sturdy, inexpensive, easily insertable and removable device for retaining idler rolls in fixed position within a bracket has long been recognized. Several attempts have been made to realize these goals with varying degrees of success. One of the most common approaches has been to provide an upwardly opening U-shaped seat to receive the end of the idler roll, aligned apertures in the upper ends of the arms of the seat, and a wedge member of sufficient length to span the opening and press against the end of the idler roll. One representative wedge configuration is disclosed in U.S. Pat. No. 2,391,272, granted Dec. 18, 1945 to David Rose. The wedges, however, even when irmly driven into place, exhibit a tendency to work loose from the apertures as the idler rolls are transported to a job site.
Another common approach has been to provide a resilient spring clip that is secured to the bracket and fits over the end cap of the idler roll to capture the roll within an aperture in the bracket. One representative clip configuration is disclosed in U.S. Pat. No. 3,157,272, granted Nov. 17, 1964, to James Bay.
The strength of such resilient clips, however, which make contact with the roll over a small area is sorely limited, so that the vibrations encountered during transport of an idler roll assembly to a job site may cause the clip to spring out of locking position; at the least, the clip may be deformed and its strength and effectiveness diminished. Also, two resilient clips are required for each idler roll, i.e., one clip for each end of the roll, and the insertion of a pair of clips into the closely spaced supports of an interior bracket of an idler roll set may prove to be difficult to accomplish. Similarly, two wedges are normally utilized for each idler roll, and the accurate insertion of the wedges within the confines of an interior bracket may also prove to be a difficult task.
Another common, and probably more successful, attempt to realize the goals set forth above has been to provide a rigid sheet metal clip having a planar body and a pair of depending legs. Short, downwardly extending flanges are formed at opposite sides of the body. Ears or tabs are struck in the depending legs, and cooperating abutments are formed in the bracket proximate to its upper end. The ends of the adjacent rolls are positioned in upwardly opening apertures or slots in the sidewalls of the support posts. Then the clip is forced downwardly over the ends of the idler rolls until the ears and abutments interengage to lock the rolls in fixed position within the post. The flanges press downwardly against the idler rolls. A representative rigid clip configuration is disclosed in U.S. Pat. No. 2,843,432, granted on July 15, 1958 to A. J. Kindig.
While one rigid clip can hold a pair of rolls in fixed position, and the rigid clip is thus well suited for use with the interior brackets on an in-line, idler roll assembly, commonly used to support a troughing conveyor, the clip disclosed in the Kindig patent necessitates the modification of existing brackets to form appropriate abutments thereon, or alternatively, the manufacture of specially designed brackets having such abutments. Furthermore, the tabs struck in the depending legs are relatively small in size and limited in strength, so that upwardly directed forces caused by the vibration of the rolls during transport may shear off the tabs and permit the rolls to "bounce" out of the bracket.